Drug delivery device with indicator

ABSTRACT

Systems and methods for monitoring an operational state and/or a fill status of a drug container of a drug delivery device are provided. The drug container can hold a liquid drug. A plunger can be positioned within the drug container. A drive system can advance the plunger to expel the liquid drug from the container. A monitoring system can detect a movement and/or a position of the plunger and/or any component coupled to the plunger. The detection can enable determination of an amount of liquid drug that has been expelled and/or an amount of liquid drug remaining in the drug container. Dosing rates, flow rates, and dosage completion can also be determined.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.15/676,604, filed Aug. 14, 2017, which claims the benefit of U.S.Provisional Application No. 62/374,881, filed Aug. 14, 2016, U.S.Provisional Application No. 62/375,026, filed Aug. 15, 2016, U.S.Provisional Application No. 62/385,749, filed Sep. 9, 2016, U.S.Provisional Application No. 62/449,845, filed Jan. 24, 2017, and U.S.Provisional Application No. 62/449,849, filed Jan. 24, 2017, all ofwhich are incorporated herein by reference in its entirety.

TECHNICAL FIELD

Embodiments generally relate to medication delivery. More particularly,embodiments relate to wearable drug delivery devices.

BACKGROUND

Many conventional drug delivery devices expel a liquid drug from a drugcontainer for delivery to a patient. These conventional drug deliverydevices often fail to inform the patient as to the fill status of thedrug container. As a result, the patient is often unaware of how muchliquid drug has been provided to the patient, when a desired dose hasbeen completed, and/or how much liquid drug remains in the drugcontainer. Accordingly, there is a need for a monitoring system for usein drug delivery devices that can determine and provide the patient withthe fill status of the drug container holding the liquid drug.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary drug container.

FIG. 2 illustrates a first exemplary drug delivery system.

FIG. 3 illustrates a second exemplary drug delivery system.

FIG. 4 illustrates a portion of an exemplary encoded needle conduit.

FIG. 5 illustrates a top view of an exemplary drug delivery device.

FIG. 6 illustrates a third exemplary drug delivery system.

FIG. 7 illustrates an optical monitoring system.

FIG. 8 illustrates an exemplary arrangement of an attenuating light pipeand a non-attenuating light pipe depicted in FIG. 7.

FIG. 9 illustrates an exemplary arrangement of the attenuating lightpipe depicted in FIGS. 7 and 8.

FIG. 10 illustrates an exemplary operation of the optical monitoringsystem depicted in FIG. 7.

FIG. 11 illustrates an exemplary monitoring system.

FIG. 12 illustrates operation of the exemplary monitoring system of FIG.11.

FIG. 13 illustrates a second exemplary monitoring system.

FIG. 14 illustrates a top view of the exemplary monitoring system ofFIG. 13.

FIG. 15 illustrates a portion of the exemplary monitoring system of FIG.13.

DETAILED DESCRIPTION

This disclosure presents various systems, components, and methodsrelated to a wearable drug delivery device and/or monitoring systems fordetermining a fill status of a drug container of a wearable drugdelivery device. Each of the systems, components, and methods disclosedherein provides one or more advantages over conventional systems,components, and methods.

Various embodiments include systems and methods for monitoring anoperational state and/or a fill status of a drug container of a drugdelivery device. The drug container can hold a liquid drug. A plungercan be positioned within the drug container. A drive system can advancethe plunger to expel the liquid drug from the container. A monitoringsystem can detect a movement and/or a position of the plunger and/or anycomponent coupled to the plunger. The detection can enable determinationof an amount of liquid drug that has been expelled and/or an amount ofliquid drug remaining in the drug container. Dosing rates, flow rates,and dosage completion can also be determined. Other embodiments aredisclosed and described.

FIG. 1 illustrates an exemplary drug container 102. The drug container102 can hold or store a liquid drug or other therapeutic agent 104. Thedrug container 102 can be used within a drug delivery device such as,for example, a wearable drug delivery device. A plunger 106 can be usedto expel the liquid drug 104 from the drug container 102 for delivery toa patient. A drive system or mechanism (not shown in FIG. 1 forsimplicity) can provide a force on the plunger 106 to drive or advancethe plunger 106 in a direction 108 to expel the liquid drug 104 from thedrug container 102 (e.g., to advance the plunger 106 from a firstposition to a second position further into the drug container 102 toexpel the liquid drug 104).

A needle conduit 110 can provide the expelled liquid drug 104 to apatient. As shown in FIG. 1, the needle conduit 110 can be coupled tothe plunger 106 such that the expelled liquid drug 104 exits from afirst end 112 of the drug container 102. Alternatively, the needleconduit 110 can be coupled to a second end 114 of the drug container 102such that the expelled liquid drug 104 exits from the second end 114 ofthe drug container 102. The liquid drug 104 can be provided to thepatient over one or more doses based on control of the drive mechanism.

The drug container 102 can be made of a variety of materials including,for example, glass or plastic. The drug container 102 is not limited tothe shape and size shown in FIG. 1. Instead, the drug container 102 canbe of any size or shape. In various embodiments, the drug container 102can be a prefilled or a Tillable container. In various embodiments, thedrug container 102 can be an International Organization forStandardization (ISO) drug container such as, for example, an ISO vial.

Various embodiments described herein provide systems and methods for apatient to readily determine, at any point during use of the drugcontainer 102, how much of the liquid drug 104 is held in the drugcontainer 102, how much of the liquid drug 104 has been expelled fromthe drug container 104, and/or when a desired dose of the liquid drug104 has been provided to the patient. Various embodiments describedherein provide systems and methods for determining this informationbased on a position or movement of the plunger 106 and/or based on aposition or movement of the drive mechanism used to advance the plunger106 (or any component of a drug delivery device coupled thereto). Suchinformation allows the patient to confirm proper dose delivery and toverify proper operation of the drug delivery device in which the drugcontainer 102 is used. Without such knowledge, the patient may not beable to confirm whether any liquid drug 104 remains in the drugcontainer 102, how much of the liquid drug 104 has been delivered to thepatient, and/or how much of the liquid drug 104 remains to be deliveredto the patient. Conventional drug delivery devices do not providemechanisms for readily determining such information regarding theoperational state and/or fill status of drug containers such as theexemplary drug container 102.

FIG. 2 illustrates a first exemplary drug delivery system 200. The drugdelivery system 200 can include the drug container 102. The drugdelivery system 200 can further include a drive mechanism for drivingthe plunger 106 in the direction 108 to expel the stored liquid drug104. As an example, the drive mechanism can include a drive spring 202and a number of spherical elements or components 204 (e.g., a pluralityof spherical elements or spheres 204). The spherical elements 204 can bereferred to as spherical energy transfer elements or components, orforce transfer spheres. As used herein, the spherical elements 204 canbe referenced using any of these terms including, for example, spheres204.

The spherical elements 204 can be positioned within a track (not shownin FIG. 2 for simplicity). The drive spring 202 can expand in adirection 206 to push the spherical elements 204 towards the plunger106. The force from the drive spring 202 is transferred to the plunger106 by the spherical elements 204 to drive the plunger 106 in thedirection 108, thereby expelling the liquid drug 104 from the drugcontainer 102. A direction of movement of the spherical elements 204 inresponse to the expansion of the drive spring 202 is shown by indicators208.

The drug delivery system 200 further includes a needle mechanism 210.The needle mechanism 210 is coupled to the needle conduit 110. Expelledliquid drug 104 is transferred to the needle mechanism 210 by the needleconduit 110, which then provides the expelled liquid drug 104 to thepatient. The drug delivery system 200 can be part of a drug deliverysystem such as, for example, a wearable drug delivery system. The drivemechanism (e.g., the drive spring 202 and the spherical elements 204) ofthe drug delivery system 200 is exemplary as a variety of differentdrive mechanisms can be used to expel the liquid drug 104 by advancingthe plunger 106 in the direction 108.

The drug delivery system 200 can include a number of mechanisms and/orsystems for determining the position of the plunger 106 within the drugcontainer 106. The position of the plunger 106 within the drug container102 can be used to determine how much liquid drug 104 remains in thedrug container 102 and/or how much liquid drug 104 has been expelledfrom the drug container 102. Based on one or more of thesedeterminations, proper operation of the drug delivery system 200 anddosing of the liquid drug 104 can be verified. The position of theplunger 106 within the drug container 102 can be determined directlyand/or can be determined based on positional information of one or moreother components of the drug delivery system 200 as further describedherein.

As shown in FIG. 2, the drug delivery system 200 can further include oneor more sensors such as, for example, a first sensor 212 positioned nearthe first end 112 of the drug container 102 and a second sensor 214positioned near the second end 114 of the drug container 102. Thesensors 212 and 214 can be used to determine how much liquid drug 104remains in the drug container 102 and/or how much liquid drug 104 hasbeen expelled from the drug container 102 based on a determination ofthe position of the plunger 106 within the drug container 102 and/orbased on a position of one or more components of a drive mechanism usedto advance the plunger 106.

In various embodiments, the sensors 212 and 214 can be Hall effectsensors that can detect the movement and/or position of the plunger 106and/or the spherical elements 204. For example, as the plunger 106 andthe spherical elements 204 move in the direction 108 and into the drugcontainer 102, the sensors 212 and 214 can detect the movement of theplunger 106 and/or the spherical elements 204. As a result, anindication of the position of the plunger 106 within the drug container102 can be determined, thereby providing a determination of how muchliquid drug 104 has been expelled and/or remains in the drug container102.

In various embodiments, the sensors 212 and 214 can determine how manyspherical elements 204 have passed by each respective sensor 212 and214. Based on a known size of each spherical element 204, adetermination on the position of the plunger 106 and/or the rate ofmovement of the plunger 106 can be made. In various embodiments, thesensors 212 and 214 can determine a position of the plunger 106 alongany portion of the drug container 102. In various embodiments, anynumber of sensors can be used. As Hall effect sensors, the sensors 212and 214 can measure a varying magnetic field resulting from movementand/or a change in position of the plunger 106 and/or the sphericalelements 204.

In various embodiments, the spherical elements 204 can comprise ametallic material. In various embodiments, the spherical elements 204can include a metallic core that is surrounded by a non-metallicmaterial such as plastic or rubber. In various embodiments, thespherical elements 204 can be made of different types of metal such thatthe magnetic response of each spherical element 204 as detected by thesensors 212 and 214 differs and can be distinguished. In variousembodiments, only certain spherical elements 204 can be comprised of ametallic material that can be detected by one of the sensors 212 and214. For example, every other spherical element 204 can comprise ametallic material that can be detected by one of the sensors 212 and214. Based on a predetermined arrangement of the spherical elements 204,as the drive mechanism advances the plunger 106, positional informationof the plunger 106 can be determined.

In various embodiments, a portion of the plunger 106 can comprise ametallic material such that the sensors 212 and 214 can detect theposition of the plunger 106 within the drug container 102. In variousembodiments, any number of sensors can be used and can be arranged alongthe drug container 102. The detection of the position of the plunger 106is not limited to the drive mechanism shown in FIG. 2. In general, thedrug delivery system 200 can include any drive system configured suchthat the sensors 212 and 214 can be used to detect the position of theplunger 106 based on detection of the plunger 106 position directlyand/or detecting a position of any portion of a drive system used toadvance the plunger 106 in the direction 108. For example, the drivesystem can include a push rod, one or more cylinders, and/or one or moresprings for driving movement of the plunger 106 with the sensors 212 and214 operating to detect the position or movement of any of thesecomponents. Any of the techniques described herein for determining thefill status of a drug container 102 and/or a position or movement of theplunger 106, either directly or indirectly, are applicable to any suchdrive mechanism, such as those described above, as will be appreciatedby a person of ordinary skill in the art.

In general, as Hall effect sensors, the sensors 212 and 214 can detectand measure a magnetic field as it varies as the plunger 102 and thespherical elements 204 are advanced in the direction 108. The sensors212 and 214 can each generate signals indicative of the measuredmagnetic field. A controller (not shown in FIG. 2) can be coupled to thesensors 212 and 214 and can receive signals generated by the sensors 212and 214. The controller can detect characteristic waveformscorresponding to the plunger 102 and/or the spherical elements 204 (orany other component of a drive system) so as to track a movement orposition of the plunger and/or the spherical elements 204 and/or count anumber spherical elements 204 that pass each of the sensors 212 and 214.In general, based on signals generated by the sensors 212 and 214, thecontroller can determine a position of the plunger 106 within the drugcontainer 102. In this way, the controller can determine a fill statusof the drug container 102 and/or the beginning or end of the stroke ofthe plunger 106.

In various embodiments, the sensors 212 and 214 can be optical sensors.In various embodiments, the sensors 212 and 214 can detect the positionof the plunger 106 based on optical detection. As an example, the drugdelivery system 200 can include a first light emitting device or lightsource 216 and a second light emitting device or light source 218. Afirst light beam 220 emitted by the first light emitting device 216 canbe detected by the first sensor 212 and a second light beam 222 emittedby the second light emitting device 218 can be detected by the secondsensor 214. The first and second light beams 220 and 222 emitted fromthe first and second light emitting devices 216 and 218, respectively,can be interrupted or blocked by the plunger 106 and/or the sphericalelements 204 (or any other drive mechanism component) as the drivemechanism drives the plunger 106 in the direction 108. As an example,the sensors 212 and 214 and corresponding light sources 216 and 218 canpositioned off center from a central axis of the spherical elements 204such that, as the spherical elements 204 are advanced, reception of thelight beams 220 and 222 by the sensors 212 and 214, respectively, can beoccasionally interrupted.

The sensors 212 and 214 can detect these interruptions in detection ofthe first and second light beams 220 and 222, respectively, and can usethe detections to determine the position of the plunger 106. In variousembodiments, the sensors 212 and 214 can count the number of sphericalelements 204 that have passed into the drug container 102 by counting anumber of interruptions, thereby providing an estimate of the positionof the plunger 106. In various embodiments, the position of the plunger106 can be determined as the plunger 106 itself interrupts lightdetection by a number of sensors positioned along the drug container102.

In various other embodiments, the sensors 212 and 214 themselves canemit light and can detect reflected light from any portion of theplunger 106 and/or any portion of the drive mechanism (e.g., thespherical elements 204). In various embodiments, the plunger 106 and/orthe spherical elements 204 can be coated with different light absorbingand/or reflecting materials, such that each element reflects and/orabsorbs light differently. Based on the light reflected by the elements,the sensors 212 and 214 can detect the advancement of the plunger 106and/or the spherical elements 204 and therefore the position of theplunger 106.

In general, the sensors 212 and 214 and operation thereof to detect theposition of the plunger 106 can be independent of the drive mechanismused to advance the plunger 106. As noted above, the position of theplunger 106 can be determined based on sensors 212 and 214 as Halleffect sensors or optical sensors. The sensors 212 and 214 can beelectrically coupled to a controller (not shown in FIG. 2) that candetermine the position of the plunger 106 based on information collectedor determined by the sensors 212 and 214. The sensors 212 and 214 canform a portion of a monitoring system for the drug delivery system 200that can determine an operational state or fill status of the drugcontainer 102 such that how much liquid drug 104 has been expelled orremains in the drug container 102 can be determined. The monitoringsystem of which the sensors 212 and 214 can be a part can aid thisdetermination based on detection of a position and/or movement of theplunger 106 and/or any component of a drive system used to advance theplunger 106.

FIG. 3 illustrates a second exemplary drug delivery system 300. The drugdelivery system 300 can operate in a similar manner with respect to thedrug delivery system 200 to expel the liquid drug 104 from the drugcontainer 102 for delivery to the patient. As shown in FIG. 3, the drugdelivery system 300 can include a needle conduit 302 and one or moresensors such as, for example, a first sensor 304 and a second sensor306. The needle conduit 302 can be an encoded needle conduit asdescribed further herein. In various embodiments, the needle conduit 302can be encoded along its length in a manner to reveal or indicatepositional information of the needle conduit 302 as it moves with theplunger 106 as the plunger 106 is advanced into the drug container 102.The first and second sensors 304 and 306 can detect the encodedpositional information of the needle conduit 302 to thereby determinethe position of the plunger 106.

In various embodiments, the needle conduit 302 can comprise a metaltubing that is coated in various regions with a non-conductive coating.The sensors 304 and 306 can detect the conductive and non-conductiveregions of the needle conduit 302. As the needle conduit 302 advancesand passes over the sensors 304 and 306 (e.g., making electrical contactwith the sensors 304 and 306), the sensors 304 and 306 can distinguishthe conductive and non-conductive regions. The sensors 304 and 306 canbe coupled to a controller (not shown in FIG. 3) that tracks the countand/or length of these different regions. Based on a predeterminedarrangement of the conductive and non-conductive regions of the encodedneedle conduit 302—for example, based on the number of different regionsand their lengths or sizes—the controller can determine the position ofthe plunger 106. Further, the controller can determine a rate ofmovement of the plunger 106. This information can then be used todetermine a fill status of the drug container 103 and a dosing status ofthe liquid drug 104.

The sensors 304 and 306 can be arranged to be coupled to the needleconduit 302 as the needle conduit 302 advances in response to movementof the plunger 106. The sensors 304 and 306 can further be arranged tonot interfere with the drive mechanism (e.g., the spherical elements204). Further, any number of sensors can be arranged to be coupled tothe needle conduit 302.

FIG. 4 illustrates a portion of an exemplary encoded needle conduit 400.The encoded needle conduit 400 can represent the needle conduit 302depicted in FIG. 3. As shown in FIG. 4, the encoded needle conduit 400includes conductive regions 402 and non-conductive regions 404. Theconductive regions 404 can be spaced apart by a distance 406. The sizesof the conductive regions 402 and the non-conductive regions 404 (andtherefore the distance 406) of the encoded needle conduit 400 can beuniform but is not so limited. In general, any known or predeterminedarrangement of the conductive regions 402 and the non-conductive regions404 can be used to determine the position of the plunger 106. Theconductive regions 402 can exhibit substantially the same or differentlevels of conductivity that can also be used to determine a positionand/or a movement of the plunger 106.

As the sensors 304 and 306 detect and/or come into electrical contactwith the conductive regions 402 and/or the non-conductive regions 404,the sensors 304 and 306 can distinguish the conductive regions 402 fromthe non-conductive regions 404 and can determine what portion of theencoded needle conduit 400 is passing over each of the sensors 304 and306. The sensors 304 and 306 can further detect the rate of movement ofthe encoded needle conduit 400 and can estimate a position and/ormovement of the plunger 106 relative to the position and/or movement ofthe encoded needle conduit 400.

In various embodiments, the sensors 304 and 306 can be optical sensors.In various embodiments, the needle conduit 302 can marked in a mannerfor the sensors 304 and 306 to detect positional information of theneedle conduit 302. For example, the needle conduit 302 can be lasermarked or etched so as to distinguish different segments of the needleconduit 302 that the sensors 304 and 306 can identify. As anotherexample, the needle conduit 302 can be marked with one or more bar codesalong one or more portions of the needle conduit 302 so as todistinguish different segments of the needle conduit 302 that thesensors 304 and 306 can identify. As the marked needle conduit 302passes over the sensors 304 and 306, the sensors 304 and 306 (e.g., asbarcode readers) can optically detect what portion of the encoded needleconduit 302 is passing each of the sensors 304 and 306, enabling theposition of the plunger 106 to be determined.

The sensors 304 and 306 and the encoded needle conduit 302 can form aportion of a monitoring system for the drug delivery system 300 that candetermine an operational state and/or fill status of the drug container102 such that how much liquid drug 104 has been expelled or remains inthe drug container 102 can be determined. The monitoring system of whichthe sensors 304 and 306 and the needle conduit 302 can be a part can aidthis determination based on detection of a position and/or movement ofthe needle conduit 302 that is coupled to the plunger 106.

In various embodiments, a window or viewing area can be positioned on adrug delivery device to enable the patient to view a portion of a drugcontainer and/or a portion of the drive mechanism to enable the patientto determine the fill status of the drug container and/or theoperational status of the drug container. The window can be part of anydrug delivery device or drug delivery system described herein and can beused in conjunction with any mechanism described herein for determiningthe fill status of a drug container.

FIG. 5 illustrates a top view of an exemplary drug delivery device 500.As shown in FIG. 5, the drug delivery device 500 can include an upperportion 502. The upper portion 502 can be a top portion or a cover ofthe drug delivery device 500. The drug delivery device 500 can furtherinclude a raised portion 504. The raised portion 504 can be elongatedand can run along a side of the drug delivery device 500. A containerfor holding a liquid drug can be approximately positioned under theraised portion 504 such that the raised portion 504 accommodates thesize and positioning of the liquid drug container within the drugdelivery device 500. As an example, a container such as the drugcontainer 102 can be positioned under the raised portion 504. Any drugdelivery system described herein can be positioned within the drugdelivery device 500.

The upper portion 502 of the drug delivery device 500 can include awindow or viewing area 506. The window 506, for example, can be made ofplastic and can be transparent. The window 506 can be of any size andshape and can be positioned on any portion of the drug delivery device500. The window 506 can allow a patient to view internal components ofthe drug delivery device 500 such as, for example, a portion of the drugcontainer positioned within the drug delivery device 500 (e.g., under aportion of the raised portion 504) and/or a portion of the drivemechanism coupled to the drug container. The patient can determine howmuch liquid drug is in an internal drug container by viewing the drugcontainer through the window 506.

In various embodiments, the spherical elements 204 can be differentlycolored to indicate a dosing status of the liquid drug 104 (and/or afill status of the drug container 102). For example, the window 506 canbe positioned on the upper portion 502 to allow a user to view all or aportion of the drug container 102. The spherical elements 204 can bedriven into the drug container 102 as the spherical elements 204 push onthe plunger 106. The user can view the spherical elements 204 enter thedrug cartridge 102. The spherical elements 204 can be coloreddifferently (or marked or otherwise visually distinguished) in apredetermined sequence or manner to indicate how much of the liquid drug104 has been expelled from the drug container 102. The marking orcoloring of the spherical elements 204 can be adjusted based on the sizeof a dose of the liquid drug 104 or an entire amount of liquid drug 104stored in the drug container 102.

For example, an initial set of spherical elements 204 can be marked in afirst manner (e.g., by a first color such as green) to indicate aninitial expulsion of the liquid drug 104 when the initial set ofspherical elements 204 enter the drug container 102 and can be viewed.An intermediate set of spherical elements 204 can be marked in a secondmanner (e.g., by a second color such as yellow) to indicate anintermediate expulsion of the liquid drug 104 when the intermediate setof spherical elements 204 enter the drug container 102 and can also beviewed. A final set or final spherical element 204 can be marked in athird manner (e.g., by a third color such as red) to indicate a finalexpulsion of the liquid drug 104 (e.g., end of dose or completion ofdose) when the final set or final spherical element 204 enters the drugcontainer 102 and is visible to the user through the window 506.

As will be appreciated by a person of ordinary skill in the art, anytype of marking (e.g., coloring) including text or other symbols and anynumber of groupings and corresponding distinctions (e.g., number ofintervals or gradations) can be used to indicate the dosing status orthe fill status of the drug container 102 based on the sphericalelements 204 entering the drug container 102. Further, as will beappreciate by a person of ordinary skill in the art, any drive mechanismcomponent used to drive the plunger 106—including, for example, a pushrod, one or more cylinders, and/or one or more springs—that enters thedrug container 102 can be marked in a manner to indicate dosing statusor fill status of the drug container 102 based on the extent to whichany portion of the drive mechanism component has entered the drugcontainer 102. Further, any marking or coloring of any component of thedrive system can be based on a predetermined dose size and/or a totalamount of the liquid drug 104 stored in the drug container 102. Invarious embodiments, the drive mechanism component or components can bemarked to simply indicate a completion of a dose—for example, when a redcolored portion of the drive mechanism is visible in the drug container102, dose completion can be indicated.

In various embodiments, a sensor can be positioned adjacent to the drugcontainer 102 that can track or a count a number of the sphericalelements 204 or other drive system components that enter the drugcontainer 102 to provide an indication of dosing status or fill statusof the drug container 102. For example, with reference to FIG. 2, asensor can be positioned adjacent to a first end 112 of the drugcontainer 102. The sensor can mechanically or can electromechanicallycount a number of the spherical elements 204 that pass the sensor as thespherical elements 204 enter the drug container 102. In variousembodiments, the sensor can be a switch that is triggered each time aspherical element 204 passes the sensor. The switch could be implementedas a mechanical switch or can be implemented as an electromechanicalswitch. As part of an electromechanical system, the sensor can becoupled to a display (e.g., an LED display) for indicating dosing statusor fill status of the drug container 102. A mechanical implementationcan include a wheel that has different colors or symbols indicating dosestatus that can be rotated by the passing of the spherical elements 204.

FIG. 6 illustrates a third exemplary drug delivery system 600. The drugdelivery system 600 can include features of the drug delivery system 200and can further include a dosing wheel 602. The dosing wheel 602 caninclude a number of arms or spokes 604 that radially extend from a hub.The dosing wheel 602 can have any number of arms 604. One or more of thearms 604 can be positioned between adjacent spheres 204. The dosingwheel 602 can rotate in a direction 606 as shown about an axis of thedosing wheel 602 to move the spheres 204 forward toward the drugcontainer 102. The drive spring 202 can provide the force to move thespheres 204 as regulated by the dosing wheel 602. That is, the dosingwheel 602 can impede forward movement of the spheres 204 until thedosing wheel 602 rotates a desired amount in the direction 606. The drugdelivery device 600 can operate as a single dose or multiple dose drugdelivery device by regulating movement of the spheres 204.

In various embodiments, movement of the dosing wheel 602 can trigger acounter or other device to track rotational movement of the dosing wheel602. For example, a counter coupled to the dosing wheel 602 can trackthe number of times the dosing wheel 602 has advanced a single sphere204 forward. In doing so, the counter can provide the patient with anindication of how much liquid drug 104 has been delivered. In variousembodiments, the counter can be coupled to the dosing wheel 602mechanically. For example, the counter can be coupled to a gear systemof the dosing wheel 602 and/or can be arranged to be triggered bycontact with the arms 604 as the arms 604 rotate. In variousembodiments, the dosing wheel 602 can be coupled to a controller (notshown in FIG. 6) that can track the rotational movement of the dosingwheel 602 and can provide an indication of the filling status of thedrug container 102 to the patient.

In various embodiments, the drug delivery system 600 can be housedwithin a device (e.g., the drug delivery device 500) having a window 608(shown in phantom). The window 608 can enable a user to view a portionof the dosing wheel 602, a portion of the drug container 102, and/or aposition of the plunger 106 within the drug container 102. In variousembodiments, the window 608 can be positioned over a portion of thedosing wheel 602 to allow the patient to view the rotation of the arms604. In various embodiments, the arms 604 of the dosing wheel 602 can bedifferently colored (e.g., color coded) or otherwise distinguishedvisually (e.g., by text or other symbols or markings) to indicate howfar the dosing wheel 602 has rotated, thereby providing an indication ofhow far the plunger 106 has advanced into the drug container 102.

FIG. 7 illustrates an optical monitoring system 700 for determining theamount of liquid drug stored in a drug container. As shown in FIG. 7,the optical monitoring system 700 includes a printed circuit board (PCB)702, a drug container 704, a plunger 706, an attenuating light pipe 708,a non-attenuating light pipe 710, a light emitting source 712, and adetector 714.

The drug container 704 can be positioned adjacent to the PCB 102 and canstore a liquid drug or other therapeutic agent. The plunger 706 can bepositioned within the drug container 704 and can be used to expel theliquid drug from the drug container 704. The plunger 706 can include ahead portion 716 and a base or rod portion 718. The rod 718 can extendout of the drug container 704. A drive mechanism (not shown in FIG. 7)can drive the plunger 706 in a direction 720 to expel stored liquid drugfrom the drug container 704 for delivery to a patient. The plunger caninclude a reflective portion 722 such as, for example, a reflectiveO-ring. The reflective O-ring 722 can be positioned on the head portion716 of the plunger 706. The reflective portion 722 can reflect lightthat is incident on the plunger 706.

The light emitting source 712 can be a light emitting diode (LED). Thedetector 714 can be a photodiode. The non-attenuating light pipe 710 canbe positioned on top of the attenuating light pipe 708. The attenuatinglight pipe 708 can be coupled to the light emitting source 712. Thelight pipes 708 and 710 can be positioned adjacent to the drug container704. The attenuating light pipe 708 can be configured to emit light fromthe light emitting source 712 out of the attenuating light pipe 708. Thenon-attenuating light pipe 710 can be configured to receive lightreflected off the reflective portion 722 and to provide the receivedlight to the detector 714. In various embodiments, the attenuating lightpipe 708 can be configured to emit light from the attenuating light pipeat a first angle and the non-attenuating light pipe 710 can beconfigured to receive light from a second angle that is orthogonal tothe first angle. The first and second angles are not limited to beingorthogonal to one another. In various embodiments, the first and secondangles can be acute or obtuse to one another. In various embodiments,the first and second angles can be oriented to adjust the effectiveintensity of light energy received by the non-attenuating light pipe710.

The light emitting source 712 can emit light and provide emitted lightinto the attenuating light source 708. Light provided to the attenuatinglight pipe 708 from the light emitting source 712 can then be emittedfrom the attenuating light pipe 708. The attenuating light pipe 708 canbe configured to attenuate the light it receives along the length of theattenuating light pipe 708. Specifically, light emitted from theattenuating light pipe 708 that is further from the light emittingsource 712 can be attenuated more than light emitted from theattenuating light pipe 708 that is closer to the light emitting source712. The non-attenuating light pipe 710 is not specifically configuredto attenuate light within the non-attenuating light pipe 710. Thenon-attenuating light pipe 710 can be coupled to the detector 714 suchthat light received by the non-attenuating light pipe 710 can beprovided to the detector 714.

A reflector 724 can be positioned between the attenuating light pipe 708and the non-attenuating light pipe 710. In various embodiments, thereflector 724 can be positioned over a top surface of the attenuatinglight pipe 708 and below a button surface of the non-attenuating lightpipe 710. The reflector 724 can prevent light from passing between theattenuating light pipe 708 and the non-attenuating light pipe 710 (e.g.,directly passing). The reflector 714 can be a film or painted componentpositioned between the attenuating light pipe 708 and thenon-attenuating light pipe 710 or provided on a surface of one of theattenuating light pipe 708 and the non-attenuating light pipe 710.

The light emitting source 712 can provide a stable source of light tothe attenuating light pipe 708. The light provided to the attenuatinglight pipe 708 can be emitted from the attenuating light pipe 708 alongthe length of the attenuating light pipe 708. The emitted light canilluminate the internal portion of the drug container 704 and theplunger 706. A portion of the light that enters the drug container 704from the attenuating light pipe 708 can be reflected by the reflectiveportion 722. This reflected light can then be received by thenon-attenuating light pipe 710. The light received by thenon-attenuating light pipe 710 can then be provided to the detector 714.

The detector 714 can determine an intensity of the light received orprovided to the detector 714. The detector 714 can generate a signalbased on the intensity of light received. As the plunger 706 moves alongthe length of the drug container 704, light of different intensitieswill be reflected off of the reflective portion 722 of the plunger 706.In general, the intensity of the reflected light can vary linearly withthe movement of the plunger 706 based on the characteristics of theattenuating light pipe 708. The detector 714 can detect the changingintensity of the received light that is reflected off the reflectiveportion 722. Based on the intensity of the received light, the detector714 can determine a position of the reflective portion 722 and thereforethe plunger 706 within the drug container 704. In turn, a determinationof how much liquid drug remains in the drug container can be made.Further, the measured signals from the detector 714 can be used todetermine a rate of movement of the plunger 706. Depending on themovement of the plunger 706 relative to the light emitting source 712,the intensity of the light detected by the detector 714 can increase ordecrease as the plunger 706 advances further into the drug container704.

As shown in FIG. 7, the optical monitoring system 700 is arranged toprovide relatively lower attenuated light to the detector 714 when theplunger 706 is positioned closer to the light source 712 (and to providerelatively higher attenuated light to the detector 714 when the plunger706 is positioned closer to the detector 714). As a result, theintensity of the light provided to the detector 714 will increase as theplunger 706 is advanced to expel additional liquid drug from the drugcontainer 704. The optical monitoring system 700 is not limited to thisarrangement. In various embodiments, the optical monitoring system 700can be arranged such that the intensity of the light provided to thedetector 714 will decrease as the plunger 706 is advanced to expeladditional liquid drug from the drug container 704. Overall, the opticalmonitoring system 700 can be arranged to provide light to the detector714 that varies in intensity based on movement of the plunger 706 (e.g.,advancement of the plunger 706 to expel the liquid drug). A controller(not shown in FIG. 7) coupled to the detector 714 can detect a positionof the plunger 706 based on the signals generated by the detector 714that indicate the intensity of light received by the detector 714.

The optical monitoring system 700 can be used with any drug containerstoring a liquid drug that is expelled by any linear translatingcomponent having a reflective portion. For example, the drug container102 and the plunger 106 can be used in the optical monitoring system700. Further, any portion of the plunger 706 can be reflective includingany component coupled to the plunger 706 that moves with the plunger 706to expel a stored liquid drug. The drug container 704 used with theoptical monitoring system can be a transparent container (or a portionthereof can be transparent).

The optical monitoring system 700 can use any type of radiationemitting/detecting pair such as, for example, an infrared, a visiblelight, or an ultraviolet source of radiation and corresponding detector.The optical monitoring system 700 can include a controller (not shown inFIG. 7) that can be coupled to the light emitting source 712 and thedetector 714. The controller can be configured to control operation ofthe light emitting source 712 and/or the detector 714. Signals generatedby the detector—for example, signals indicating a position of theplunger 706 based on a detected intensity of reflected lightreceived—can be provided to the controller. The controller cansubsequently determine a position and movement of the plunger 706 or anycomponent of the drive system for operating the plunger 706 based onsignals generated by the detector 714. The controller can furtherdetermine how much liquid drug has been expelled and/or how much liquiddrug remains in the drug container 704.

FIG. 8 illustrates an exemplary arrangement of the attenuating lightpipe 708 and the non-attenuating light pipe 710 depicted in FIG. 7. Asshown in FIG. 8, the attenuating light pipe 708 and the non-attenuatinglight pipe 710 can each include windows 808 for emitting light andreceiving light, respectively. Certain windows 808 can be covered withan anti-reflective (e.g., non-transmissive) coating 802 such that nolight is emitted or received through a window 808 coated withanti-reflective coating 802.

For the attenuating light pipe 708, the anti-reflective coating 802 canbe placed on the windows 808 that are oriented at a first angle relativeto the light emitted by the light emitting source 712. As such, as shownin FIG. 8, light can only be passed through those windows 808 that arenot covered by the anti-reflective coating 802. The windows 808 of theattenuating light pipe 708 that can pass light can be oriented at asecond angle that is orthogonal to the first angle as shown. Indicator804 shows an exemplary direction of light that can be emitted or passedfrom the attenuating light pipe 708.

For the non-attenuating light pipe 710, the anti-reflective coating 802can be placed on windows 808 that are orthogonal to the windows 808 ofthe attenuating light pipe 708 that are coated with the anti-reflectivecoating 802 as shown in FIG. 8. Accordingly, the non-attenuating lightpipe 710 can receive light through windows 808 that are orthogonal tothe windows 808 of the attenuating light pipe 708 that can emit light,but are not so limited. That is, the windows 808 of the attenuatinglight pipe 708 that emit light can be oriented according to any anglewith respect to the windows 808 of the non-attenuating light pipe 710.In various embodiments, the windows 808 for emitting and receiving lightcan be oriented at an obtuse or an acute angle with respect to oneanother. In general, the angle of orientation can be adjusted to providea desired effective intensity for the light energy received by thenon-attenuating light pipe 710.

Indicator 806 shows an exemplary direction of light that can be receivedby the non-attenuating light pipe 710. The arrangement of the windows808 and the coated windows 802 of the attenuating light pipe 708 and thenon-attenuating light pipe 710 can ensure that attenuated light emittedby the attenuating light pipe 708 is directed toward the detector 714after it reflects off the plunger 706. In particular, reflected lightfrom the plunger 706 can pass through an uncoated window 808 of thenon-attenuating light pipe 710 and then directed toward the detector714.

FIG. 9 illustrates an exemplary arrangement of the attenuating lightpipe 708 depicted in FIGS. 7 and 8. Emitted light 902 represents thelight emitted from the light emitting source 712 and its intensity(e.g., as indicated by a size of the corresponding arrow representingthe light). The emitted light 902 can travel down the attenuating lightpipe 708 and can exit from windows 808 that are not covered with coating802. Emitted light 904-1 through 904-5 represents the light that passesthrough each corresponding window 808 and its intensity. The attenuatinglight pipe 708 can be configured to have an attenuation profile thatattenuates the emitted light 902 more the further the light is from thelight emitting source 712 (e.g., compare the relatively higher intensityof the emitted light 904-1 to the relatively lower intensity emittedlight 904-5). Accordingly, the intensity of the light that is emittedfrom the windows 808 that are closer to the light emitting source712—such as, emitted light 904-1—can be greater than the intensity ofthe light that is emitted from the windows 808 that are further from thelight emitting source 712—such as, emitted light 904-5.

The different levels of intensities of the emitted light 904-1 through904-5 can be reflected off the reflective portion 722 of the plunger 706as the plunger 706 advances into the drug container 704 and moves alongthe length of the attenuating light pipe 708 as described above. Assuch, the intensity of the light received by the detector 714 can change(e.g., increase or decrease as the plunger 706 moves further into thedrug container 704 depending upon the arrangement of the components ofthe optical monitoring system 700). The varying intensity of the lightreceived by the detector 714 can be used to determine a position of theplunger 706. For example, the emitted light 904-1, when reflected off ofthe reflective portion 722 and then received by the non-attenuatinglight pipe 710 and the detector 714, can indicate a first position ofthe plunger 706. Correspondingly, emitted light 904-5, when reflectedoff of the reflective portion 722 and then received by thenon-attenuating light pipe 710 and the detector 714, can indicate asecond, different position of the plunger 706. In various embodiments,the detector 714 can generate a signal indicative of the intensity ofthe received light. The signal can be provided to the controller thatcan then use the signal to determine a position and/or movement of theplunger 706. The fill status of the drug container 704 (e.g., how muchliquid drug remains in the drug container 704 or has been expelled) canthen be determined.

The attenuating light pipe 708 can be configured to have any attenuationprofile. In various embodiments, the attenuating light pipe 708 can beconfigured to have a linear attenuation profile. The attenuating lightpipe 708 can be formed of a material having a homogenous attenuationprofile that can scatter and/or absorb light to cause attenuation. Ingeneral, as light travels further into the attenuation light pipe 708,more attenuation is provided, thereby causing larger decreases inintensity in the light as it travels further into the attenuating lightpipe 708 (e.g., further away from the light source 712). The attenuatinglight pipe 708 can be made from various types of materials includingplastics and can be covered with an attenuation coating or othermaterial. In various embodiments, the attenuating light pipe 708 can beformed from polymethylmethacrylate (PMMA).

FIG. 10 illustrates an exemplary operation of the optical monitoringsystem 700. As shown in FIG. 10, the attenuating light pipe 708 ispositioned on top of the non-attenuating light pipe 710. The reflector724 is positioned between the attenuating light pipe 708 and thenon-attenuating light pipe 710. A light beam 1002 is shown entering theattenuating light pipe 708. The light beam 1002 can be provided by thelight emitting source 712 depicted in FIG. 7. The light beam 1002 cantravel along the attenuating light pipe 708 and can exit as anattenuated version of the light beam 1002 from any of the windows 808that are not coated windows 802. For example, the light beam 1002 canexit a first window 1020 along the attenuated light pipe 708 as a firstexit light beam 1004. The first exit light beam 1004 can be anattenuated version of the light beam 1002. The first exit light beam1004 can be attenuated by a first amount relative to the intensity ofthe light beam 1002.

The light beam 1002 can further exit a second window 1022 along theattenuated light pipe 708 as a second exit light beam 1012. The secondexit light beam 1012 can be also be an attenuated version of the lightbeam 1002. Indicator 1024 can specify a direction of increasingattenuation by the attenuating light pipe 708. Specifically, theattenuating light pipe 708, as described herein, can attenuate the lightbeam 1002 more further along the length of the attenuating light pipe708 relative to an entry point of the light beam 1002. Accordingly, thefirst exit light beam 1004 can be attenuated less than the second exitlight beam 1012. For purposes of explanation, the first exit light beam1004 is shown to be wider than the second exit light beam 1012 torepresent that the second exit light beam 1012 is more attenuated thanthe first exit light beam 1004. The second exit light beam 1012 can beattenuated by a second amount relative to the intensity of the lightbeam 1002.

Object 1006 can represent a first position of the plunger 706 (and/or aposition of any reflective portion of the plunger 706). As shown in FIG.10, the first exit light beam 1004 is reflected off the object 1006 as afirst reflective light beam 1008. The first reflective light beam 1008can pass through any of the windows 808 of the non-attenuating lightpipe 710 that are not coated windows 802. The first reflective lightbeam 1008 can then travel through the non-attenuating light pipe 710 andcan be provided to the detector 714 depicted in FIG. 7.

Indicator 1010 represents a travel path of the plunger 706. As shown inFIG. 10, the travel path 1010 of the plunger 706 can be substantiallyparallel to the arrangement of the attenuating and non-attenuating lightpipes 708 and 710. Object 1014 can represent a second position of theplunger 706 (and/or a position of any reflective portion of the plunger706). As shown in FIG. 10, the second exit light beam 1012 is reflectedoff the object 1014 as a second reflective light beam 1016. The secondreflective light beam 1016 can pass through any of the windows 808 ofthe non-attenuating light pipe 710 that are not coated windows 802. Thesecond reflective light beam 1016 can then travel through thenon-attenuating light pipe 710 and can be provided to the detector 714depicted in FIG. 7.

Light beam 1018 can represent light that exits the non-attenuating lightpipe 710 and is provided to the detector 714. The light beam 1018 can bean attenuated version of the light beam 1002. The level of attenuationexperienced by the light beam 1018 can be substantially based on thelevel of attenuation experienced by the initial light beam 1002 from theattenuating light pipe 708, which is then reflected by the plunger 706.For example, the light beam 1018 will experience less attenuation andwill be more intense if the plunger 706 is positioned closer to a firstend 1024 of the attenuating light pipe 708 in comparison to when theplunger 706 is positioned closer to a second end 1026 of the attenuatinglight pipe 708. That is, when the position of the plunger 706 can berepresented by the object 1006, the intensity of the light beam 1018will be relatively larger (e.g., due to relatively lower experiencedattenuation) since the first reflective light beam 1008 is reflected offof the plunger 706. When the position of the plunger 706 can berepresented by the object 1014, the intensity of the light beam 1018will be relatively smaller (e.g., due to relatively higher experiencedattenuation) since the second reflective light beam 1016 is reflectedoff the plunger 706.

The detector 714 can detect the light beam 1018. As described herein,the detector 714 can measure an intensity of the light beam 1018. Forexample, the detector 714 can generate a signal based on the measuredintensity of the light beam 1018. Signals generated by the detector 714can be provided to a controller (not shown in FIG. 10). The controllercan determine a position of the plunger 706 within the drug container704 based on the signal provided to the controller by the detector 714.For example, the controller can determine the plunger 706 is positionedcloser to the first end 1024 of the attenuating light pipe 708 when thedetector 714 generates a signal in response to a relatively more intenselight beam 1018. The controller can determine the plunger 706 ispositioned closer to the second end 1026 of the attenuating light pipe708 when the detector 714 generates a signal in response to a relativelyless intense light beam 1018. The position of the plunger 706 relativeto the drug container 704 can therefore be determined, enabling adetermination of how much liquid drug remains in the drug container orhow much liquid drug has been expelled from the drug container 704.Further determinations such as a rate of movement of the plunger 706 canalso be determined.

FIG. 11 illustrates an exemplary monitoring system 1100. The monitoringsystem 1100 can include a drug container 1102. A portion of the drugcontainer 1102 is shown in FIG. 11. The drug container 1102 can hold orstore a liquid drug 1104. The monitoring system 1100 can further includea plunger 1106 positioned in the drug container 1102. The plunger 1106can be moved or advanced to expel the liquid drug 1104 from the drugcontainer 1102. The drug container 1102 can represent the drug container102. The plunger 1106 can be moved to expel the liquid drug 1104 out ofeither end of the drug container 1102 as will be appreciated by a personhaving ordinary skill in the art, for example as described above inrelation to FIG. 2.

As shown in FIG. 11, the monitoring system 1100 can also include anumber of pins 1108. The pins 1108 can be positioned within the drugcontainer 1102. The pins 1108 can be molded into the drug container1102. The pins 1108 can be made from a conductive material such as ametal. The pins 1108 can be positioned and shaped so as to be flush(aligned) or approximately flush with an inner or interior surface ofthe drug container 1102. The pins can also be positioned and shaped soas to be flush (aligned) or approximately flush with an outer or outsidesurface of the drug container 1102.

As shown in FIG. 11, seven (7) pins 1108 are shown as inserted moldedinto the drug container 1102—pins 1108-1 through 1108-7. Any number ofpins 1108 can be positioned in the drug container 1102 and can bearranged in any manner. The liquid drug 1104 stored in the drugcontainer 1102 can provide electrical conductivity between the pins1108. A controller and/or other circuitry coupled to the pins 1108 (notshown in FIG. 11 for simplicity) can monitor the electrical connectivityof the pins 1108 relative to one another and/or the liquid drug 1106. Asthe plunger 1106 is moved to expel the liquid drug 1104 from the drugcontainer 1102, a portion of the pins 1108 can become electricallydecoupled from the other pins 1108 and/or the liquid drug 1104. Thecontroller can monitor the changing status of the electricalconnectivity of the pins 1108 to determine a position and/or movement ofthe plunger 1106. In this way, the monitoring system 1100 can determinea fill status of the drug container 1102 and/or other informationregarding dosing rate, an amount of the liquid drug 1104 expelled fromthe drug container 1102, and/or a rate of movement of the plunger 1106.As shown in FIG. 11, all of the pins 1108-1 through 1108-7 can beelectrically coupled to one another as each pin 1108 is coupled to theliquid drug 1104.

FIG. 12 illustrates the monitoring system 1100 after a portion of theliquid drug 1104 has been expelled from the drug container 1102. Asshown in FIG. 12, the plunger 1106 has moved past the pins 1108-1through 1108-3 and is positioned adjacent to the pin 1108-4. The pins1108-1 through 1108-4 are no longer coupled to the liquid drug 1104.Consequently, the pins 1108-1 through 1108-4 are no longer electricallyconnected or coupled to any other pin 1108. The controller coupled tothe pins 1108 can determine which pins 1108 are electrically coupledtogether (e.g., and/or coupled to the liquid drug 1104) and candetermine a position of the plunger 1104. For example, as shown in FIG.12, the controller can determine that a front surface of the plunger1106 (e.g., a surface of the plunger in contact with the liquid drug1104) can be positioned between the pin 1108-4 and the pin 1108-5. Thecontroller can also determine that pins 1108-5 through 1108-7 areelectrically connected and coupled to the liquid drug 1104. Accordingly,the monitoring system 1100 allows an approximate position of the plunger1106 to be determined. In turn, the monitoring system 110 can determinehow much of the liquid drug 1104 remains in the drug container 1102 andhow much liquid drug 1104 has been expelled from the drug container1102.

As mentioned above, the monitoring system 1100 can use number of pins1108. The pins 1108 can be spaced apart from one another by a fixeddistance but are not so limited. As will be appreciated by a person ofordinary skill in the art, the monitoring system 1100 can use more pins1108 to provide a better or more accurate approximation as to thelocation of the plunger 1106 within the drug container (and therefore abetter or more accurate approximation of the fill status of the drugcontainer 1102).

FIG. 13 illustrates a second exemplary monitoring system 1300. Themonitoring system 1300 can include a drug container 1302. The drugcontainer 1302 can hold or store a liquid drug 1306. The monitoringsystem 1300 can further include a plunger 1304 positioned in the drugcontainer 1302. The plunger 1304 can be moved or advanced to expel theliquid drug 1306 from the drug container 1302. The drug container 1302can represent the drug container 102. The plunger 1304 can be moved toexpel the liquid drug 1306 out of the drug container 1302 through afluid path 1308 (e.g., by moving toward the fluid path 1308). As will beappreciated by a person of ordinary skill in the art, the plunger 1302and the fluid path 1308 can be arranged to enable the liquid drug 1306to be expelled through the plunger 1304 (e.g., through an opposite endof the drug container 1302 from what is shown in FIG. 13), for exampleas described above in relation to FIG. 2.

As shown in FIG. 13, the monitoring system 1300 can further include afirst conductive component or trace 1310, a second conductive componentor trace 1312, a third conductive component or trace 1314, a firstconductive pin 1316, a second conductive pin 1318, and a thirdconductive pin 1320. The traces 1310, 1312, and 1314 and the pins 1316,1318, and 1320 can be formed of an electrically conductive material. Aconductive ring or wiper 1322 can be positioned around the plunger 1034.The ring 1322 can be formed of an electrically conductive material.

The first trace 1310 can be coupled to the pin 1318. The first trace1310 can be positioned inside of the drug container 1302. The firsttrace 1310 can be coupled to an inner surface of the drug container1302. The first trace 1310 can extend along a substantial portion of alongitudinal length of the drug container 1302.

The second trace 1312 can be coupled between the pin 1318 and the pin1316. The second trace can also be coupled to the inner surface of thedrug container 1302. The second trace can also extend along asubstantial portion of the longitudinal length of the drug container1302. The second trace 1312 can be formed of a material having anincreasing resistance (e.g., a linearly increasing resistance).

The third trace 1314 can be coupled to the pin 1316 and the pin 1320.The third trace 1314 can be positioned outside of the drug container1302. The third trace 1314 can be coupled to an outer surface of thedrug container 1302. The third trace 1314 can extend along a substantialportion of the longitudinal length of the drug container 1302.

A portion of the pin 1318 can extend into the drug container 1302 and aportion of the pin 1318 can extend outside of the drug container 1302. Aportion of the pin 1316 can also extend into the drug container 1302 anda portion of the pin 1316 can also extend outside of the drug container1302. The pin 1320 can be positioned on the outside of the drugcontainer 1302. The portions of the pins 1318 and 1316 that extend intothe drug container 102 and the traces 1310 and 1312 can be in contactwith the liquid drug 1306 stored in the drug container 1302. The trace1314 and the pin 1320 can be positioned so as to not be in contact withthe liquid drug 1306.

The pins 1318 and 1320 can be coupled to one or more output circuitsand/or a controller (not shown in FIG. 13 for simplicity). The traces1310, 1312, and 1314, and the pins 1316, 1318, and 1320 can form avariable resistive network. The variable resistive network can be usedto determine a position of the plunger 1306 within the drug container1302, enabling a fill status of the drug container 1302 to bedetermined. As the plunger 1304 moves from an initial position (e.g., ator near a far end of the drug container 1302) toward the fluid path1308, the ring 1322 electrically couples (e.g., shorts) the trace 1310to the trace 1312 along different corresponding portions of the traces1310 and 1312. Coupling the trace 1310 to the trace 1312 completes acircuit. Based on the variable resistivity of the trace 1312, thecoupling of the trace 1310 to the trace 1312 completes a circuit havingdifferent resistance values based on the location of the plunger 1304.

For example, when the ring 1322 couples the trace 1310 to the trace 1312at a far end of the drug container 1302 (e.g., in close proximity to thepin 1316), the completed circuit can have a relatively lower resistance,as only a relatively small portion of the trace 1312 is included in thecompleted circuit (due to the shorting of the traces 1310 and 1312 bythe ring 1322). When the ring 1322 couples the trace 1310 to the trace1312 at a near end of the drug container 1302 (e.g., in closer proximityto the fluid path 1308 and/or the pin 1318), the completed circuit canhave a relatively higher resistance, as a relatively larger portion ofthe trace 1312 is included in the completed circuit. Inclusion of alarger portion of the trace 1312 in the completed circuit results in thecompleted circuit having relatively higher resistance values, such thatmovement of the plunger 1304 can result in completed circuits ofincreasing resistance (e.g., linearly increasing resistance). Thecompleted circuit—referenced to the pins 1318 and 1320—can be providedor coupled to the controller or other output circuits. Based on thevariable resistance of the completed circuit, the controller candetermine a position of the plunger 1304 and therefore a fill status ofthe drug container 1302.

FIG. 14 illustrates a top view of the monitoring system 1300 depicted inFIG. 13. The arrangement of the traces 1310, 1312, and 1314 along thelength of the drug container 1302 is shown. Further, the electricalcoupling of the trace 1310 and the trace 1312 by the ring 1322 isillustrated. The circuit completed by the ring 1322 includes largerportions of the trace 1312 as the plunger 1304 moves closer to the fluidpath 1308. Accordingly, a controller coupled to the output pins 1318 and1320 can determine the position of the plunger 1304 based on thevariable (e.g., increasing) resistance of the completed circuit.

FIG. 15 illustrates a portion of the monitoring system 1300.Specifically, FIG. 15 illustrates the traces 1310, 1312, and 1314 andthe pins 1316, 1318, and 1320. These components can be considered toform a variable resistive network as described above (or a portion of apotentiometer as will be appreciated by a person of ordinary skill inthe art). The trace 1312 is shown to have a zigzag shape but is not solimited. In various embodiments, the trace 1312 can be a form asubstantially straight trace.

As described herein, systems and methods for monitoring an operationalstate and/or fill status of a drug container have been provided. Each ofthe monitoring systems described herein can be combined with any otherdescribed monitoring system. The described monitoring systems can becoupled to a user interface device. For example, a controller of themonitoring systems can be coupled to a remote user interface device(e.g., a mobile device) and can provide a patient or user withnotifications regarding a fill status of a drug container. In variousembodiments, the notification can alert a user to an amount of liquiddrug expelled and/or remaining. In various embodiments, the notificationcan alert a user to when a desired dose of liquid drug has been providedto a patient and/or when the drug container is empty. In variousembodiments, the notification can indicate a dosing rate or flow rate ofthe liquid drug being delivered to the patient. Notifications to thepatient can include audible notifications, visual notifications, and/orvibrational notifications. In various embodiments, any describedcontroller can be considered to be a part of any of the describedsensors or can be considered to be a separate component of themonitoring systems described herein. In various embodiments, themonitoring systems can associate plunger position with a time stamp suchthat flow rates, dosing rate, and/or a dosing profile for delivery of aliquid drug to the patient can be determined. In various embodiments,the monitoring systems described herein can be implemented in a wearabledrug delivery device.

The following examples pertain to further embodiments:

Example 1 is an apparatus comprising a drug container configured to holda liquid drug, a plunger positioned in the drug container, a drivesystem coupled to the plunger, the drive system configured to advancethe plunger to expel a portion of the liquid drug from the drugcontainer for delivery to a patient, and one or more sensors positionedadjacent to the drug container, the one or more sensors configured todetect a position of the plunger within the drug container.

Example 2 is an extension of Example 1 or any other example disclosedherein, further comprising a controller coupled to the one or moresensors.

Example 3 is an extension of Example 2 or any other example disclosedherein, wherein the controller is configured to determine an amount ofthe liquid drug remaining in the drug container based on the detectedposition of the plunger.

Example 4 is an extension of Example 2 or any other example disclosedherein, wherein the controller is configured to determine the portion ofthe liquid drug expelled from the drug container based on the detectedposition of the plunger.

Example 5 is an extension of Example 2 or any other example disclosedherein, wherein the controller is configured to determine a dosing rateof the portion of the liquid drug expelled from the drug container basedon the detected position of the plunger.

Example 6 is an extension of Example 2 or any other example disclosedherein, wherein the controller is configured to determine when a desireddose of the liquid drug has been provided to the patient based on thedetected position of the plunger.

Example 7 is an extension of Example 2 or any other example disclosedherein, wherein the controller is configured to provide a notificationto the patient indicating a fill status of the drug container based onthe detected position of the plunger.

Example 8 is an extension of Example 7 or any other example disclosedherein, wherein the notification indicates a desired dose of the liquiddrug has been provided to the patient.

Example 9 is an extension of Example 7 or any other example disclosedherein, wherein the notification comprises at least one of an audiblenotification, a visual notification, and a vibrational notification.

Example 10 is an extension of Example 2 or any other example disclosedherein, wherein the one or more sensors are configured to detect aposition of a component of the drive system within the drug container.

Example 11 is an extension of Example 10 or any other example disclosedherein, wherein the component of the drive system comprises one or morespherical elements.

Example 12 is an extension of Example 11 or any other example disclosedherein, wherein the component of the drive system comprises a drivespring.

Example 13 is an extension of Example 12 or any other example disclosedherein, wherein each of the one or more sensors comprise a Hall effectsensor.

Example 14 is an extension of Example 13 or any other example disclosedherein, wherein each Hall effect sensor is configured to count a numberof spherical elements that pass the Hall effect sensor.

Example 15 is an extension of Example 13 or any other example disclosedherein, wherein the one or more Hall effect sensors detect an end of astroke of the plunger.

Example 16 is an extension of Example 13 or any other example disclosedherein, wherein a first Hall effect sensor is positioned adjacent to afirst end of the drug container and a second Hall effect sensor ispositioned adjacent to a second, opposite end of the drug container.

Example 17 is an extension of Example 12 or any other example disclosedherein, wherein each of the one or more sensors comprise an opticalsensor.

Example 18 is an extension of Example 17 or any other example disclosedherein, further comprising one or more light sources, each light sourcecorresponding to one of the one or more optical sensors.

Example 19 is an extension of Example 18 or any other example disclosedherein, wherein each light source is configured to emit light toward thecorresponding optical sensor and wherein each optical sensor isconfigured to receive the corresponding light.

Example 20 is an extension of Example 19 or any other example disclosedherein, wherein each optical sensor is configured to detect when atleast one of the plunger and the spherical elements interrupts receptionof the corresponding light beam.

Example 21 is a method comprising positioning a plunger in a drugcontainer holding a liquid drug, advancing the plunger further into thedrug container using a drive system to expel the liquid drug from thedrug container, delivering the expelled liquid drug to a patient, anddetecting a position of the plunger within the drug container using oneor more sensors positioned adjacent to the drug container.

Example 22 is an extension of Example 21 or any other example disclosedherein, further comprising determining an amount of the liquid drugremaining in the drug container based on the detected position of theplunger.

Example 23 is an extension of Example 21 or any other example disclosedherein, further comprising determining an amount of the liquid drugexpelled from the drug container based on the detected position of theplunger.

Example 24 is an extension of Example 21 or any other example disclosedherein, further comprising determining a dosing rate of the liquid drugexpelled from the drug container based on the detected position of theplunger.

Example 25 is an extension of Example 21 or any other example disclosedherein, further comprising determining when a desired dose of the liquiddrug has been provided to the patient based on the detected position ofthe plunger.

Example 26 is an extension of Example 21 or any other example disclosedherein, further comprising providing a notification to the patientindicating a fill status of the drug container based on the detectedposition of the plunger.

Example 27 is an extension of Example 26 or any other example disclosedherein, wherein the notification indicates a desired dose of the liquiddrug has been provided to the patient.

Example 28 is an extension of Example 26 or any other example disclosedherein, wherein the notification comprises at least one of an audiblenotification, a visual notification, or a vibrational notification.

Example 29 is an extension of Example 21 or any other example disclosedherein, further comprising detecting a position of a component of thedrive system within the drug container.

Example 30 is an extension of Example 29 or any other example disclosedherein, further comprising detecting the position of the plunger or thecomponent of the drive system based on measuring a varying magneticfield, wherein each of the one or more sensors are Hall effect sensors.

Example 31 is an extension of Example 21 or any other example disclosedherein, further comprising detecting the position of the plunger or thecomponent of the drive system based on detecting an interruption inreceiving an emitted light, wherein each of the one or more sensors areoptical sensors.

The following examples pertain to further additional embodiments:

Example 1 is an apparatus comprising a drug container configured to holda liquid drug, a plunger positioned in the drug container, a needleconduit coupled to the plunger, a drive system coupled to the plunger,the drive system configured to advance the plunger to expel a portion ofthe liquid drug from the drug container through the needle conduit fordelivery to a patient, and one or more sensors coupled to the needleconduit and configured to detect a position of the plunger within thedrug container based on corresponding advancement of the needle conduit.

Example 2 is an extension of Example 1 or any other example disclosedherein, wherein the needle conduit comprises one or more conductiveregions and one or more non-conductive regions.

Example 3 is an extension of Example 2 or any other example disclosedherein, wherein the one or more conductive regions and the one or morenon-conductive regions are arranged in a predetermined manner.

Example 4 is an extension of Example 3 or any other example disclosedherein, wherein each of the one or more conductive regions are of apredetermined size.

Example 5 is an extension of Example 3 or any other example disclosedherein, wherein each of the one or more non-conductive regions are of apredetermined size.

Example 6 is an extension of Example 3 or any other example disclosedherein, wherein each of the one or more sensors are electrical sensors.

Example 7 is an extension of Example 6 or any other example disclosedherein, wherein the one or more sensors detect the one or moreconductive regions and the one or more non-conductive regions of theneedle conduit as the needle conduit advances in response to advancementof the plunger by the drive system.

Example 8 is an extension of Example 7 or any other example disclosedherein, further comprising a controller coupled to the one or moreelectrical sensors.

Example 9 is an extension of Example 8 or any other example disclosedherein, wherein the controller is configured to determine the positionof the plunger based on electrical signals provided by the one or moreelectrical sensors.

Example 10 is an extension of Example 9 or any other example disclosedherein, wherein the controller is configured to determine an amount ofthe liquid drug remaining in the drug container based on the detectedposition of the plunger.

Example 11 is an extension of Example 9 or any other example disclosedherein, wherein the controller is configured to determine the portion ofthe liquid drug expelled from the drug container based on the detectedposition of the plunger.

Example 12 is an extension of Example 9 or any other example disclosedherein, wherein the controller is configured to determine a dosing rateof the liquid drug expelled from the drug container based on thedetected position of the plunger.

Example 13 is an extension of Example 9 or any other example disclosedherein, wherein the controller is configured to determine when a desireddose of the liquid drug has been provided to the patient based on thedetected position of the plunger.

Example 14 is a method comprising positioning a plunger in a drugcontainer configured to hold a liquid drug, advancing the plungerfurther into the drug container to expel the liquid drug from the drugcontainer through a needle conduit coupled to the plunger, deliveringthe expelled liquid drug to a patient, and determining a position of theplunger using one or more sensors coupled to the needle conduit.

Example 15 is an extension of Example 14 or any other example disclosedherein, further comprising determining an amount of the liquid drugremaining in the drug container based on the detected position of theplunger.

Example 16 is an extension of Example 14 or any other example disclosedherein, further comprising determining an amount of the liquid drugexpelled from the drug container based on the detected position of theplunger.

Example 17 is an extension of Example 14 or any other example disclosedherein, further comprising determining a dosing rate of the liquid drugbased on the detected position of the plunger.

Example 18 is an extension of Example 14 or any other example disclosedherein, further comprising determining when a desired dose of the liquiddrug has been provided to the patient based on the detected position ofthe plunger.

Example 19 is an extension of Example 14 or any other example disclosedherein, further comprising providing a notification to the patientindicating the detected position of the plunger.

Example 20 is an extension of Example 19 or any other example disclosedherein, wherein the notification indicates a desired dose of the liquiddrug has been provided to the patient.

Example 21 is an extension of Example 14 or any other example disclosedherein, further comprising detecting one or more conductive regions ofthe needle conduit using the one or more sensors.

Example 22 is an extension of Example 21 or any other example disclosedherein, further comprising detecting one or more non-conductive regionsof the needle conduit using the one or more sensors.

Example 23 is an extension of Example 22 or any other example disclosedherein, wherein determining the position of the plunger comprisesdetecting the one or more conductive regions of the needle conduit anddetecting the one or more non-conductive regions of the needle conduit.

Example 24 is an extension of Example 22 or any other example disclosedherein, wherein the one or more sensors are electrical sensors.

The following examples pertain to further additional embodiments:

Example 1 is an apparatus comprising a drug container configured tostore a liquid drug, a plunger positioned in the drug container, a drivesystem coupled to the plunger, the drive system configured to advancethe plunger to expel a portion of the liquid drug from the drugcontainer for delivery to a patient, and an optical monitoring systemconfigured to determine a position of the plunger within the drugcontainer.

Example 2 is an extension of Example 1 or any other example disclosedherein, wherein the optical monitoring system is configured to determinea fill status of the drug container based on the determined position ofthe plunger.

Example 3 is an extension of Example 2 or any other example disclosedherein, wherein a portion of the drug container is transparent.

Example 4 is an extension of Example 3 or any other example disclosedherein, wherein the plunger comprises a reflective portion.

Example 5 is an extension of Example 4 or any other example disclosedherein, wherein the reflective portion is a reflective O-ring.

Example 6 is an extension of Example 5 or any other example disclosedherein, wherein the reflective O-ring is positioned on a head of theplunger.

Example 7 is an extension of Example 4 or any other example disclosedherein, wherein the optical monitoring system comprises a light source.

Example 8 is an extension of Example 7 or any other example disclosedherein, wherein the light source is a light emitting diode (LED).

Example 9 is an extension of Example 7 or any other example disclosedherein, wherein the optical monitoring system comprises an attenuatinglight pipe coupled to the light source.

Example 10 is an extension of Example 9 or any other example disclosedherein, wherein the optical monitoring system comprises anon-attenuating light pipe.

Example 11 is an extension of Example 10 or any other example disclosedherein, wherein the optical monitoring system comprises a detectorcoupled to the non-attenuating light pipe.

Example 12 is an extension of Example 11 or any other example disclosedherein, wherein the detector is a photodiode.

Example 13 is an extension of Example 11 or any other example disclosedherein, wherein the attenuating light pipe is positioned over thenon-attenuating light pipe.

Example 14 is an extension of Example 13 or any other example disclosedherein, wherein the attenuating light pipe and the non-attenuating lightpipe are positioned adjacent to the drug container.

Example 15 is an extension of Example 14 or any other example disclosedherein, wherein a reflective component is positioned between theattenuating light pipe and the non-attenuating light pipe.

Example 16 is an extension of Example 15 or any other example disclosedherein, wherein the attenuating light pipe is configured to attenuatelight emitted by the light source.

Example 17 is an extension of Example 16 or any other example disclosedherein, wherein the attenuating light pipe is configured to attenuatethe light emitted by the light source according to an attenuationprofile.

Example 18 is an extension of Example 17 or any other example disclosedherein, wherein the attenuation profile is linear.

Example 19 is an extension of Example 17 or any other example disclosedherein, wherein the attenuating light pipe is configured to emit anattenuated version of the light emitted by the light source.

Example 20 is an extension of Example 19 or any other example disclosedherein, wherein the light emitted by the attenuating light pipe isattenuated based on a distance traveled by the light emitted by thelight source through the attenuating light pipe.

Example 21 is an extension of Example 19 or any other example disclosedherein, wherein the light emitted by the attenuating light pipe isreflected off of the reflective portion of the plunger.

Example 22 is an extension of Example 21 or any other example disclosedherein, wherein the non-attenuating light pipe receives light reflectedoff of the reflective portion of the plunger.

Example 23 is an extension of Example 22 or any other example disclosedherein, wherein the received light is provided to the detector.

Example 24 is an extension of Example 23 or any other example disclosedherein, wherein the detector generates a signal based on the receivedlight.

Example 25 is an extension of Example 24 or any other example disclosedherein, wherein the signal indicates an amount of attenuation of thelight emitted by the light source.

Example 26 is an extension of Example 25 or any other example disclosedherein, wherein the signal is provided to a controller coupled to thedetector.

Example 27 is an extension of Example 25 or any other example disclosedherein, wherein the controller determines the position of the plungerbased on the signal.

Example 28 is a method, comprising providing light from a light sourceto an attenuating light pipe, attenuating the light according to anattenuation profile of the attenuating light pipe, emitting theattenuated light from the attenuating light pipe, reflecting theattenuated light from a reflective portion of a plunger positioned in adrug container configured to hold a liquid drug, and providing thereflected attenuated light to a detector.

Example 29 is an extension of Example 28 or any other example disclosedherein, further comprising receiving the reflected attenuated light in anon-attenuating light pipe.

Example 30 is an extension of Example 29 or any other example disclosedherein, further comprising generating a signal based on the reflectedattenuated light.

Example 31 is an extension of Example 30 or any other example disclosedherein, further comprising indicating an amount of attenuation of thelight provided to the attenuating light pipe in the generated signal.

Example 32 is an extension of Example 31 or any other example disclosedherein, further comprising providing the generated signal to acontroller.

Example 33 is an extension of Example 32 or any other example disclosedherein, further comprising determining a relative position of theplunger in the drug container based on the generated signal.

Example 34 is an extension of Example 33 or any other example disclosedherein, further comprising determining an amount of the liquid drugexpelled from the drug container based on the determined position of theplunger.

Example 35 is an extension of Example 33 or any other example disclosedherein, further comprising determining an amount of the liquid drugremaining in the drug container based on the determined position of theplunger.

Example 36 is an extension of Example 33 or any other example disclosedherein, further comprising determining when a desired dosage of theliquid drug is provided to a patient based on the determined position ofthe plunger.

Example 37 is an extension of Example 33 or any other example disclosedherein, further comprising notifying the patient of the determinedposition of the plunger.

Example 38 is an extension of Example 37 or any other example disclosedherein, further comprising notifying the patient by at least one of avisual indication, an audible indication, and a vibrational indication.

The following examples pertain to further additional embodiments:

Example 1 is an apparatus comprising a drug container configured to holda liquid drug, a plunger positioned in the drug container, a drivesystem coupled to the plunger, the drive system configured to advancethe plunger to expel a portion of the liquid drug from the drugcontainer for delivery to a patient, a plurality of conductive pinspositioned in the drug container, and a controller electrically coupledto each of the plurality of conductive pins.

Example 2 is an extension of Example 1 or any other example disclosedherein, wherein an inner surface of the drug container is aligned with afirst end surface of each conductive pin.

Example 3 is an extension of Example 2 or any other example disclosedherein, wherein the first end surface of each conductive pin is disposedin an interior of the drug container.

Example 4 is an extension of Example 2 or any other example disclosedherein, wherein an outer surface of the drug container is aligned with asecond end surface of each conductive pin.

Example 5 is an extension of Example 4 or any other example disclosedherein, wherein the second end surface of each conductive pin isdisposed in an exterior of the drug container.

Example 6 is an extension of Example 4 or any other example disclosedherein, wherein the second end surface of each conductive pin iselectrically coupled to the controller.

Example 7 is an extension of Example 1 or any other example disclosedherein, wherein the plurality of conductive pins are positioned throughthe drug container.

Example 8 is an extension of Example 1 or any other example disclosedherein, wherein the controller is configured to monitor an electricalconnectivity of each of the plurality of conductive pins.

Example 9 is an extension of Example 8 or any other example disclosedherein, wherein the controller is configured to monitor an electricalconnectivity of each of the plurality of conductive pins relative to oneanother.

Example 10 is an extension of Example 8 or any other example disclosedherein, wherein the controller is configured to monitor an electricalconnectivity of each of the plurality of conductive pins relative to theliquid drug.

Example 11 is an extension of Example 8 or any other example disclosedherein, wherein the controller is configured to determine a position ofthe plunger within the drug container based on the monitored electricalconnectivity of the plurality of conductive pins.

Example 12 is an extension of Example 11 or any other example disclosedherein, wherein the controller is configured to determine a fill statusof the drug container based on the determined position of the plunger.

Example 13 is an extension of Example 1 or any other example disclosedherein, wherein the conductive pins are evenly spaced along the drugcontainer.

Example 14 is a method comprising advancing a plunger positioned in adrug container holding a liquid drug to expel the liquid drug from thedrug container, delivering the expelled liquid drug to a patient, anddetecting an electrical connectivity between a plurality of conductivepins disposed in the drug container.

Example 15 is an extension of Example 14 or any other example disclosedherein, further comprising determining a position of the plunger withinthe drug container based on the determined electrical connectivitybetween the plurality of conductive pins.

The following examples pertain to further additional embodiments:

Example 1 is an apparatus comprising a drug container configured to holda liquid drug, a plunger positioned in the drug container, a drivesystem coupled to the plunger, the drive system configured to advancethe plunger to expel a portion of the liquid drug from the drugcontainer for delivery to a patient, and a variable resistive circuitdisposed on an inner surface of the drug container.

Example 2 is an extension of Example 1 or any other example disclosedherein, wherein the variable resistive circuit comprises a firstconductive trace positioned on the inner surface of the drug containerand coupled to a first conductive pin, a second conductive tracepositioned on the inner surface of the drug container and coupledbetween the first conductive pin and a second conductive pin, and aconductive ring positioned around an outer surface of the plungeradjacent to the inner surface of the drug container, the conductive ringelectrically coupling the first conductive trace to the secondconductive trace at a first position corresponding to a position of theplunger within the drug container.

Example 3 is an extension of Example 3 or any other example disclosedherein, wherein the second conductive trace is configured to have alinearly increasing resistance.

Example 4 is an extension of Example 3 or any other example disclosedherein, wherein the first conductive pin comprises a first portiondisposed inside of the drug container and a second portion disposedoutside of the drug container.

Example 5 is an extension of Example 4 or any other example disclosedherein, wherein the second conductive pin comprises a first portiondisposed inside of the drug container and a second portion disposedoutside of the drug container.

Example 6 is an extension of Example 5 or any other example disclosedherein, wherein the second conductive pin is coupled to a thirdconductive trace positioned on an outer surface of the drug container.

Example 7 is an extension of Example 6 or any other example disclosedherein, wherein the third conductive trace is coupled to a thirdconductive pin disposed on the outer surface of the drug container.

Example 8 is an extension of Example 7 or any other example disclosedherein, wherein a controller is electrically coupled to the first andthird conductive pins.

Example 9 is an extension of Example 8 or any other example disclosedherein, wherein the controller is configured to monitor a resistance ofthe variable resistance circuit.

Example 10 is an extension of Example 9 or any other example disclosedherein, wherein the resistance of the variable resistance circuitincreases as the plunger is advanced from a first position to a secondposition to expel the portion of the liquid drug.

Example 11 is an extension of Example 10 or any other example disclosedherein, wherein the controller is configured to determine the positionof the plunger based on the monitored resistance of the variableresistance circuit.

Example 12 is an extension of Example 11 or any other example disclosedherein, wherein the controller is configured to determine a fill statusof the drug container based on the determined position of the plunger.

Example 13 is a method comprising advancing a plunger positioned in adrug container holding a liquid drug to expel the liquid drug from thedrug container, delivering the expelled liquid drug to a patient, andmonitoring a resistance of a variable resistance circuit disposed in thedrug container to determine a position of the plunger within the drugcontainer.

Example 14 is an extension of Example 13 or any other example disclosedherein, further comprising coupling a first conductive trace of to asecond conductive trace to form the variable resistive circuit, thefirst and second conductive traces disposed on an inner surface of thedrug container.

Example 15 is an extension of Example 14 or any other example disclosedherein, wherein coupling further comprises electrically coupling thefirst and second conductive traces together by a conductive ringpositioned around the plunger.

Example 16 is an extension of Example 15 or any other example disclosedherein, further comprising measuring the resistance of the variableresistance circuit.

Example 17 is an extension of Example 16 or any other example disclosedherein, further comprising determining the position of the plunger basedon the measured resistance.

Example 18 is an extension of Example 17 or any other example disclosedherein, further comprising determining a fill status of the drugcontainer based on the position of the plunger.

Certain embodiments of the present invention were described above. Itis, however, expressly noted that the present invention is not limitedto those embodiments, but rather the intention is that additions andmodifications to what was expressly described herein are also includedwithin the scope of the invention. Moreover, it is to be understood thatthe features of the various embodiments described herein were notmutually exclusive and can exist in various combinations andpermutations, even if such combinations or permutations were not madeexpress herein, without departing from the spirit and scope of theinvention. In fact, variations, modifications, and other implementationsof what was described herein will occur to those of ordinary skill inthe art without departing from the spirit and the scope of theinvention. As such, the invention is not to be defined only by thepreceding illustrative description.

What is claimed is:
 1. An apparatus, comprising: a drug containerconfigured to hold a liquid drug; a plunger positioned in the drugcontainer; a drive system coupled to the plunger, the drive systemconfigured to advance the plunger to expel a portion of the liquid drugfrom the drug container for delivery to a patient; a plurality ofconductive pins positioned in the drug container; and a controllerelectrically coupled to each of the plurality of conductive pins.
 2. Theapparatus of claim 1, wherein an inner surface of the drug container isaligned with a first end surface of each conductive pin.
 3. Theapparatus of claim 2, wherein the first end surface of each conductivepin is disposed in an interior of the drug container.
 4. The apparatusof claim 2, wherein an outer surface of the drug container is alignedwith a second end surface of each conductive pin.
 5. The apparatus ofclaim 4, wherein the second end surface of each conductive pin isdisposed in an exterior of the drug container.
 6. The apparatus of claim4, wherein the second end surface of each conductive pin is electricallycoupled to the controller.
 7. The apparatus of claim 1, wherein theplurality of conductive pins are positioned through the drug container.8. The apparatus of claim 1, wherein the controller is configured tomonitor an electrical connectivity of each of the plurality ofconductive pins.
 9. The apparatus of claim 8, wherein the controller isconfigured to monitor an electrical connectivity of each of theplurality of conductive pins relative to one another.
 10. The apparatusof claim 8, wherein the controller is configured to monitor anelectrical connectivity of each of the plurality of conductive pinsrelative to the liquid drug.
 11. The apparatus of claim 8, wherein thecontroller is configured to determine a position of the plunger withinthe drug container based on the monitored electrical connectivity of theplurality of conductive pins.
 12. The apparatus of claim 11, wherein thecontroller is configured to determine a fill status of the drugcontainer based on the determined position of the plunger.
 13. Theapparatus of claim 1, wherein the conductive pins are evenly spacedalong the drug container.
 14. A method, comprising: advancing a plungerpositioned in a drug container holding a liquid drug to expel the liquiddrug from the drug container; delivering the expelled liquid drug to apatient; and detecting an electrical connectivity between a plurality ofconductive pins disposed in the drug container.
 15. The method of claim14, further comprising determining a position of the plunger within thedrug container based on the determined electrical connectivity betweenthe plurality of conductive pins.